In addition to games, educational and multimedia reference titles were produced, such as interactive encyclopedias, museum tours, etc., which were popular before public Internet access was widespread. Competitors included the Tandy VIS and Commodore CDTV. CD-i also refers to the multimedia Compact Disc standard used by the CD-i console, also known as Green Book, which was developed by Philips and Sony (not to be confused with MMCD, the pre-DVD format also co-developed by Philips and Sony). Work on the CD-i began in 1984 and it was first publicly announced in 1986. The first Philips CD-i player, released in 1991 and initially priced around US$700, is capable of playing interactive CD-i discs, Audio CDs, CD+G (CD+Graphics), Karaoke CDs, Photo CDs and Video CDs (VCDs), though the latter requires an optional "Digital Video Card" to provide MPEG-1 decoding.
Seen as a game console, the CD-i format proved to be a commercial failure. However, the device was sold until 1998, despite claims that Philips planned a discontinuation in 1996. Despite this, they lost nearly one billion dollars on the entire project. The failure of the CD-i caused Philips to leave the video game industry after it was discontinued. The CD-i was also one of the earliest consoles to implement internet features, including subscriptions, web browsing, downloading, e-mail, and online play. This was facilitated by the use of an additional hardware modem that Philips released in 1996 for $150.